Keyboards of various permutations and configurations have been proposed over the years to try and provide for the efficient entry of alphanumeric characters to computer devices and systems. The English QWERTY keyboard that is currently used on a number of devices evolved from the keyboard that is used for typewriters. The QWERTY layout of keys for typewriters was required to prevent the mechanical mechanism associated with the keyboard from jamming. This, of course, is no longer a problem that besets today's electronic keyboards, but the QWERTY layout is still favoured by experienced touch typists. The QWERTY layout, however, continues to pose difficulties for anyone who is not an experienced touch typist. In particular, the QWERTY layout also imposes significant difficulties for users of small computer devices.
Typing textual information quickly, easily and without error into small computer devices such as mobile telephones, personal digital assistants (PDAs), and the like, is a challenge that limits the potential use of such devices. Mobile telephones include, for example, a 10 or 12 button numeric key pad, where text entry is effected by way of multi-tapping keys or by way of Tegic T9 word disambiguation software. Text entry into such devices is generally limited to SMS messages of less than 160 characters. PDAs are typically better adapted for use in entry of longer passages of text but key layouts still pose difficulties. “Smartphones” that combine the functionality of mobile telephones and PDAs are becoming increasingly more popular, but these devices suffer the same difficulties. It is possible to connect a Smartphone or a PDA with a QWERTY keyboard, however, the addition of such a device somewhat defeats the original aim of having a small portable device.
The full QWERTY keyboard has also been miniaturised to fit small handheld computer devices with either hardware buttons and thumb-boards on recent mobile messaging devices, or as a virtual software input panel. However squeezing a 10 column QWERTY keyboard across the width of a device that can comfortably sit in the hand results in a very small key board with tiny buttons that are hard to use. Further the indicia of such keyboards are typically difficult to read and use without error. These difficulties especially impact those with poor eyesight and/or large hands.
The QWERTY keyboard is designed for two-handed use where frequent two-pair letter combinations are hit by alternate hands and different fingers. As such, if one finger, or stylus, is being used to tap the keys on a QWERTY keyboard, then considerable time is spent unproductively moving the stylus from one side of the keyboard to the other. Besides slowing down text entry, this continual hand movement can be very fatiguing after typing even short passages of text.
Text entry through handwriting recognition systems is typically slower than text entry by way of a QWERTY keyboard, for example. This is largely due to the time involved in writing and recognising a full character or word being more than the time involved in simply tapping a key.
Speech recognition systems have also been used but generally require low background noise and powerful software and hardware. Moreover, it may not always be appropriate to enter text via dictation when in the company of others. Sophisticated chording and gesture driven techniques based on shorthand techniques can typically only be applied with special interfaces and software. Furthermore, such systems generally require users to practice for a long time to acquire proficiency and acceptable productivity.
With just a single stroke or tap per character, keyboard based techniques still have potential for rapid text input. One such method involves analysis of all the letter pair frequencies in a corpus of text and use of an algorithm to create and test layouts that minimise the “travel distance” between the keys or the “travel time”. This distance-based approach has resulted in circular or square arrangements of keys of dimensions 6×5 rows with the Space keys located near the centre of the keyboard, high frequency keys closer to the centre and the lowest frequency at the far corners of the keyboard. On first appearance, these keyboards almost appear to have random, illogical letter placement. Consequently, these keyboards have proven to be difficult to learn and require a lot of practice to achieve the same level of productivity as is achievable with a QWERTY keyboard, for example.
Accordingly, it is desired to address the above, or at least provide a useful alternative.